Uninterruptible power supply device having independent bypass function

Abstract

The present invention relates to an uninterruptible power supply device comprising: a first switch for connecting an output of an inverter to a load; a second switch for connecting a bypass line to the load; and an STS control unit for controlling operations of the first switch and the second switch, wherein: the first switch includes a power switching semiconductor capable of performing active switching control; the second switch includes an SCR switch and a power switching semiconductor capable of performing active switching control, the SCR switch and the power switching semiconductor being connected to each other in parallel; and when an anomaly occurs in the inverter, the STS control unit causes an off signal to be applied to a gate of the power switching semiconductor of the first switch, which can perform active switching control, and simultaneously causes the SCR switch of the second switch to be turned on first and then the power switching semiconductor capable of performing active switching control to be sequentially turned on.

What is claimed is: 
     
         1 . An uninterruptible power supply device comprising:
 a first switch for connecting an output of an inverter to a load;   a second switch for connecting a bypass line to the load; and   an STS control unit configured to control operations of the first switch and the second switch,   wherein the first switch includes a power switching semiconductor capable of active switching control,   the second switch includes a power switching semiconductor capable of active switching control and an SCR switch, the power switching semiconductor and the SCR switch being connected in parallel with each other, and   the STS control unit performs control such that an off signal is applied to a gate of the power switching semiconductor capable of active switching control of the first switch, and simultaneously the SCR switch of the second switch is turned on first and then the power switching semiconductor capable of active switching control is sequentially turned on when an abnormality occurs in the inverter.   
     
     
         2 . The uninterruptible power supply device of  claim 1 , wherein, when an abnormality occurs in the inverter, the STS control unit performs control such that the off signal is applied to the gate of the power switching semiconductor capable of active switching control of the first switch, and simultaneously the SCR switch of the second switch is turned on first and then the power switching semiconductor capable of active switching control is sequentially turned on in a state in which a circuit breaker CB 4  of the bypass line is turned on. 
     
     
         3 . The uninterruptible power supply device of  claim 1 , wherein the second switch further includes a mechanical switch, the mechanical switch being connected in parallel with the power switching semiconductor capable of active switching control and the SCR switch of the second switch, and
 the STS control unit performs control such that the off signal is applied to the gate of the power switching semiconductor capable of active switching control of the first switch, and simultaneously the SCR switch, the mechanical switch, and the power switching semiconductor capable of active switching control of the second switch are sequentially turned on when an abnormality occurs in the inverter.   
     
     
         4 . The uninterruptible power supply device of  claim 3 , wherein the STS control unit performs control such that the SCR switch, the mechanical switch, and the power switching semiconductor capable of active switching control of the second switch are sequentially turned on, and then the SCR switch and the mechanical switch are turned off and the power switching semiconductor capable of active switching control is maintained in a turn on state. 
     
     
         5 . The uninterruptible power supply device of  claim 4 , wherein the mechanical switch is a relay or magnetic contactor (MC). 
     
     
         6 . A method of operating an uninterruptible power supply device including a first switch for connecting an output of an inverter to a load, a second switch for connecting a bypass line to the load, and an STS control unit configured to control operations of the first switch and the second switch, the first switch including a power switching semiconductor capable of active switching control, the second switch including a power switching semiconductor capable of active switching control and an SCR switch, the power switching semiconductor and the SCR switch being connected in parallel with each other, the method comprising:
 a first step (S 100 ) in which the STS control unit performs control such that an off signal is applied to a gate of the power switching semiconductor capable of active switching control of the first switch, and simultaneously the SCR switch of the second switch is turned on first and then the power switching semiconductor capable of active switching control is sequentially turned on when an abnormality occurs in the inverter; and   a second step (S 200 ) in which the STS control unit performs control such that the SCR switch, the mechanical switch, and the power switching semiconductor capable of active switching control of the second switch are sequentially turned on, and then the SCR switch and the mechanical switch are turned off and the power switching semiconductor capable of active switching control is maintained in a turn on state.   
     
     
         7 . A computer program stored in a storage medium to execute the method of operating an uninterruptible power supply device of  claim 6 .